Ore furnace



, c. "r. KNIGHT ORE FURNACE 2 Sheets-Sheet 1 Filed Oct. 29. 1928 gvwento'c June 17, 1930. c. T. KNIGHT 1,764,313

ORE FURNACE Filed Oct. 29, 192B 2 Sheets-Sheet 2 q R w w x Patented June 17, 1930 CHARLES '1. KNIGHT, OF DENVER, COLORADO PATEN 1 FER oran rUmvAcE Application filed October 29,1928. Serial No. 315,684.

This invention relates to an ore roasting furnace. Furnaces of this type must usually be lined with firebrick or other refractory material in order to protect the metal shell 5 ofthe furnace. The'principal object of this invention is to provide an ore roasting furnace in which accumulations of ore, scale,

etc. are prevented from adhering or remaining localized in the furnace shell so that blistering, distorting and burning out the shell is prevented and the necessity of a fireclay lining is avoided.

- Another object of the invention is to provide means for conveying the ore through i the furnace at a constant uniform rate and simultaneously cleaning and scouring the furnace wall A further object of the invention is to provide means for introducing and discharging ore from the furnace without at any time exposing the furnace interior to the atmosphere so that the escape of dust, gases and vapors is prevented.

A still further object of the invention is to prevent the entrance of air with feed or discharge of the ore sothat the gases and vapors from the ore are not diluted or contaminated.

A further object is to prevent any of the combustion gases or flames from reaching the interior of the roasting shell so that danger of explosion is avoided. 3

And a still further object of the invention is to provide means for collecting and saving the elements which usually pass off as gas and vapors from the furnace. Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efiiciency. These will become more apparent from the following description. In the following detailed description of the invention reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

1 is a vertical longitudinal section cent strips 20 are arranged in advance rethrough the furnace or ore roasting portion of the invention. y I

Fig. 2 is'a vertical cross section through the roastertakenon the line 22, Fig. 1.

Fig. 3 "is an enlarged vertical section ghrgu h this feed hopper taken onftheline Fig. 45 is a continuation of 1, illustrating the apparatus for treating the gases and vapors from the furnace or roaster. 69 Fig. 5 is'a detail view of the conveying or scouring brush employed in the roaster.

Fig. 6' is a detail perspective view of an alternate form of brush.

The invention in its full form'comprises a roasting cylinder 10, connected by means i of a conduit 11, to a settling, and condensatlon chamber 12 from which the gases are drawn by means of an exhaust fan13 and discharged into an absorption tank lL' 7 An axial shaft 15 passesentirely through" the roasting cylinder 10 and is journaled in bearings 16 formed in endca'ps '17 which close the extremities of 'the'cylinder. The shaft 15 can be rotated from any suitable source of power through the, medium of sprockets, chains, or'a' gear 18.

Within the cylinder 10', theshaft 15 carries a spaced series of band wheels 19 to which are secured spiral strips '20. The strips 20 are preferably arranged so that they will make approximately one complete spiral in-the' length of the. cylinder 10. In the average installation the cylinder 10 is 7 approximately thirty feet in length.

Each of the spiral strips 2 0'is provided with a series of metallic brushes 21 at spaced intervals thereon. The brushes2l on adjalation with each other so that they form? spirals about theseries of spiral strips 20.

Below the cylinder 10 a furnace chamber 23 is arrangedto which 'accessmay be had through fire doors 23. Any suitable heating 5 means may be employed in the furnace: chamber 22 such as coal grates, or oil, or gas burners, etc. The heating means form no part of the present invention and are therefore, not illustrated. A suitable flue is provided to carry off the combustion gases.

It is desired to call attention to the fact that the heating chamber and the cylinder are entirely closed to each other so that the fire or combustion gases do not come into conta'et with the 'ore at any point.

Ore is fed into the forward extremity of the cylinder 10 through a feed hopper 25 and discharged at the rearwardentremity thereof, through a discharge hopper 26. The feed hopper 25 and the discharge hopper 26 are similar in construction and each comprises a cylindrical housing 47 within whieh a bucket wheel 27 rotates. The bucket heel-s 27 are maintained upon lateral shafts 28 and are each provided with a series of bucket-s 29 which fit snugly between the flat end walls and the curved side walls of the housin s 47 o By this arrangement the ro'asti'n cylinder 10, is always closed to.the atmosp ere. Inejomingcre will fall from the ho per 25 into the buckets 29 an'd be'low'ered rotation of the shaft 28 until it is discharged from the buckets into the cylinder. As each bucket passes into the housing the next suceeeding bucket will close the housing before the previous bucket has opened tothe cylinder interior. The discharge of ore from the cylinder is similarly accomplished through the discharge hopper 26.

The spiral arrangement of the strips 20 and the spiral placement of the brushes 21 causes the latter to, pass the ore through the cylinder 10 from the feed extremity to the discharge extremity and the brushes act to simultaneously and constantly scrub and scour the interior of the cylinder 10, so that accumulations which might cause blisters and burning of the cylinder walls are entirely eliminated.

The gases emitting from the "roasting ore pass through the conduit 11 into the settling [and condensation chamber 12. The top of the chamber 12 is formed by means of a water pan 30 through which a constant stream of: cold water pa ses. The bottom of the [pan 3'0 acts as a condensation surface to condense the arsenic, sulphur, phosphorus, etc, from the hot gases flowing from the roaster.

Dust and other solidmaterials in the gases will settle to the bottom ofthe chamber 12 and can be collected through suitable clean-out-doors, such as indicated at 31. The gases are drawn from the condensation chamber-12 by means of the exhaust an orblower 13. The blowerv 13. dis arges through a check valve 32 in the absorption ank 14- 1 The principal residual gas, af;ter leaving the sett f "chamber 12, is sulphur dioxide which, is a sorbed by the water in the absorption tank 14 to form sulp "urous acid.

If desired, a constant flow can be maintained through the absorption tank from an intake pipe 33, controlled by a valve 34 and through a discharge pipe 35 cont-rolled by a valve 36. The volume of flow can be regulated by the valves 34 and 36 to adjust the flow in accordance with the volume of gases so that an acid of: uniform strength will con stantly flow from the discharge pipe 35.

, The check valve 32 prevents any liquid from flowing from the tank 14 back into the system. This check valve is lifted by the pressure of the incoming gases so as to allow the gases to bubble upwardly through the tank solution.

The metallic brushes 21 can be of any desired construction such, for instance, as illustrated in Fig. 5. This type of brush comprises a clamp band 39 which clamps a bundle of stifi? wire bristles 38 to a threaded stud 47. The projection of the stud can be regulated b means of lock nuts 40 so that the brush wil project beyond the spiral strip 20 into contact with the interior surface of the cylinder 10. B adjustment of the nuts 40 wear in the brus es can be taken An alternate form of the brush is illustrated in Fig. '6 and comprises a brush block 41 in which a flat sheet'of spring steel or similar metallic spring material 42 is clamped by means of a clamp bolt 43. The sheet 42 is split into a series of brush members as shown at 44. The brush block 41 is carried on a threaded stud 45 which is similarly ad'ustable in the spiral strip 20 by means 0 lock nuts 46.

lVhen using the furnace on ores that do not have a condensible product such as arsenic and the like, the condensation chamber 12 can be eliminated and the conduit 11 connected directly to thee'xhaust fan 13.-

teri'al into the forward extremity of saidcylinder; means for discharging material from the rearward extremity of said cylinder ;'an axial shaft passing through said cylinder; and a series of flexible metallic brushessupported from said shaft and ar- "ranged to contact withthe interior surface" 'of said cylinder; andmeans for heating the exterior surface of said cylinder.v V

2. An ore furnace comprising: a horizontally placed cylinder; means for feeding material into the forward extremity or said cylinder; means for discharging material from the rearward extremity of said cylinder; an axial shaft passing through said cylinder; and a series of metallic brushes supported from said shaft and arranged to contact with the interior surface of said cylinder; a series of spiral strips extending throughout said cylinder and supporting said brushes; a series of band wheels carried by said shaft and supporting said strips in spaced relation; and means for heating a portion of the external surface of said cylinder.

3. Means for conveying material through and cleaning the internal surface of, a furnace cylinder comprising: a shaft assing through said cylinder; a series 0 band wheels carried by said shaft; a series of spiral strips supported on the periphery of said band wheels; and a series ofbrush members projecting from said strip into contact with said cylinder.

4. Means for conveying material through and cleaning the internal surface of, a furnace cylinder comprising: a shaft assing through said cylinder; a series 0 band wheels carried by said shaft; a series of spiral strips supported on the periphery of said band Wheels; and a series of brush members projecting from said strip into contact with said cylinder, said brush members being arranged in spiral relation so as to advance material through said cylinder.

5. Means forconveying material through and cleaning the internal surface of a furnace cylinder comprising: a shaft passin through said cylinder; a series of ban wheels carried by said shaft; a series of spiral strips supported on the periphery of said band Wheels; and a series of'brush members projecting from said strip into contact with said cylinder, said brush members comprising: flexible metallic members; clamping means for holding said members; and means for adjustabl supporting said clamping means upon said spiral strips.

6. Means for conveying material through a furnace cylinder comprising: a shaft extending longitudinally within said cylinder; and a series of flexible brush members supported in spaced relation about said shaft substantially into contact with the internal surface of said cylinder.

In testimony whereof, I affix my signature.

CHARLES T. KNIGHT. 

